[algorithm of the program.]

hi. i got a task to do, and i have to use [u][b]LAMP[/b][/u]. I am slightly confused on the way it has to get implemented. all i need is some guidance (not the code). here is the problem.
i got a database of 60 users with their contact details, and there is an extra column that is manually assigned a letter A, B, or C to the user. Depending on which area is coming from, it gets a letter. A for North, Bfor east, and C for south.
week 1:
Mon to Friday each day is gonna have one person from team A
Saturday and Sunday  each day is gonna have one person from team B and one from C.
week 2:
Mon to Friday each day is gonna have one person from team B
Saturday and Sunday  each day is gonna have one person from team A and one from C.
week 3
Mon to Friday each day is gonna have one person from team C
Saturday and Sunday  each day is gonna have one person from team A and one from B.
and the story continues. have in mind that i do not want a user from a team to appear twice, unless everybody from its team have done the job. for example user A1 cannot appear again unless all users A1-A20 have not done their job.

any ideas?  ???

[troubled with queries]

hi. i got a task to finish, but i am not sure on how to implement it. the task is:
there is a database of 54 entries (with the option to add/remove entries). those entries will be in three groups ABC. group A will have the first 13, group B the next 13, and group C the rest. i want to have a script that for Monday to Friday will take from group A, one everyday and in serial mode. for weekends it will choose:
Saturday: one from B and one from C
Sunday: one from B and one from C.
this is for two months. after that period the groups rotate so it becomes:

weekdays group B
weekends group c & A.
then the next two months will be:

weekdays group C
weekends A&B.
any ideas on how to help me on that task? i am confused with the queries of php on MySQL.

thanks in adavance.